This invention relates to the regulation of the flow of molten metal, contained in a continuous casting distributor, which is itself fed by a casting ladle into the ingot molds where the metal solidifies.
It is already known to regulate such flow by means of refractory plug-nozzle elements. The plug, placed at the end of a tapping rod or bottstick, blocks the orifice of the nozzle to a greater or lesser extent by regulating the rising of the tapping rod or bottstick. The latter is raised by the action of a control which is fixed to the distributor and connected to the bottstick.
The action on the control can be manual, but it is also known to actuate the control by means of a device for measuring the level in the ingot mold. A closed regulating circuit of this kind can be produced by using suitably placed radioactive sources; however, these exhibit a number of disadvantages in use.
A closed-loop circuit, which is based on the sensing of the radiation emitted by the liquid metal in the ingot mold and has been tested industrially on a continuous casting installation of applicant's assignee together with the mechanical control forming the subject of this invention, overcomes these disadvantages and exhibits perfectly reliable operation and a remarkable stability of the level in the ingot mold. This result is obtained even in the case where pipes are used for protecting the stream of liquid metal flowing between the distributor and the ingot mold, together with synthetic slags for covering the meniscus of the liquid metal in the ingot mold.
Furthermore, it is known to design the distributor in such a way that it can be raised, lowered, moved sideways or tilted, in order to avoid the hazards of the casting process or to satisfy the necessary conditions at the beginning and end of this process, whether or not the casting is continuous. This requires easily detachable connections between the control parts attached to the distributor and those connected to the manual or automatic control components. It is necessary to reduce the intervention times to an absolute minimum and also to protect the delicate components of the automatic control; this is made possible by the invention.
It is also known that, in the case of automatic control, it is all the more difficult to start the casting process in the second case.